Sign attachment



FIG. 1 shows a perspective view;

FIG. 2 shows a front view;

FIG. 3 shows a rear view;

FIG. 4 shows a top view;

FIG. 5 shows a bottom view;

FIG. 6 shows a left side view; and,

FIG. 7 shows a right side view.

The broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a sign attachment, as shown and described. 